1. Field of the Invention
This invention relates in general to a seed planter, and in particular to an improved vacuum seed planter for test plots.
2. Description of the Prior Art
Vacuum seed planters are used to meter the amount of seeds being planted, providing for proper spacing of seeds and reducing seed waste. The vacuum planters typically have a seed plate with radially-spaced apertures and a vacuum source for creating a vacuum pressure in the apertures. The seed plate passes through a seed chamber containing seeds to be planted, individual seeds being drawn to the apertures. A singulator device removes excess seeds, preferably leaving one seed per aperture, the excess seeds falling back within the seed chamber. When changing seed types, the seed chamber is emptied through a door near the bottom of the chamber. An example of a typical vacuum planter is the Monosem NG Plus, available from A.T.I., Inc., of Lenexa, Kans.
It is also known in the art to evacuate the seed chamber using a vacuum source. One example uses a valve for redirecting the vacuum from the seed plate to the seed chamber for evacuating the chamber. In this apparatus, the seed chamber cannot be emptied while the seed plate is in use, since the vacuum pressure is switched from the seed plate to the evacuation tube.
It is desirable to plant multiple plots of seeds, each plot having a different seed type. However, the prior art planters require that the change of seed type occur in an alleyway or require two seed plates, each having a different type of seed. In the two-seed-plate device, the first plate is used to plant a plot, then the second plate is used while the seed for the first plate is changed. The extra seed plate adds additional cost, weight, and complexity to the standard seed planter.
Therefore, there is a need for a seed planter having a single seed plate and that is capable of quickly and easily planting multiple seed plots. Also, there is a need for a seed planter that ensures that seeds can be removed from the rotating seed plate between rows or when changing seed types.
A vacuum seed planter uses a single seed plate for planting multiple plots of seeds. The seed plate rotates through a seed chamber and uses vacuum pressure to pick up seeds to be planted, the seed chamber having an inlet passage for receiving seeds. A singulator dislodges excess seeds from the seed plate, and the excess seeds fall into an excess-seed compartment adjacent the seed chamber, the compartment having an outlet passage for evacuation of the excess seeds. A valve is movable between an operating position, in which the inlet passage communicates with a supply of seed and the outlet passage communicates with a vacuum source for evacuating excess seeds, and an evacuation position, in which the vacuum source is in communication with the inlet passage for evacuating the seeds in the seed chamber. Vacuum pressure on the seed plate can be maintained during evacuation of the seed chamber and excess-seed compartment.